Expression device for automatic musical instruments



C. V JAMESON.

EXPRESSION DEVICE FQR AUTOMATIC MUSICAL INSTRUMENTS.

L 2. 9 1T. n I 4 1 3 mm H M 2 APPLlCATiOH man 0m. 10. 1917. 1,367,262.

.NI/ N u l C. V. lAMESON.

EXPRESSION DEVICE FOR AUTOMATIC MUSICAL INSTRUMENTS.

APPLICATION FILED- OCT, 10, 1912.

Patented Feb. 1, 1921.

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Invenfv/f UNITED STATES PATENT ()FFICE.

CHARLES V. JAMESON. OF CHICAGO, ILLINOIS.

EXPRESSION DEVICE FOR A'UTOLEIATIC MUSICAL INSTRUMENTS.

Application filed October 10, 1917.

To all whom it may) concern:

Be it known that I, CHARLES V. J At-inson', a citizen of the United States, residing at Chicago, in the county of Cook and State of Illinois, have invented new and useful Improvements in Expression Devices for Automatic Musical Instruments of which the following is a specification.

This invention relates to the expression devices employed in auto-pneumatic musical instruments, for emphasizing or accenting selected notes or passages of a composition, and more particularly to a device of this kind which is controlled by the pedals of the exhaust pumps or feeders.

It is one object of my invention to simplify the construction of such devices.

A further object is to so organize the apparatus that parts requiring regulation or repair are easy of access.

In the accompanying drawings:

Figure 1 is a front elevation of the lower portion of a player piano embodying the improved accent device. Fig. 2 is atransverse section on line 2-2, Fig. 1. Fig. 3 is a simi lar section on line 3-3, F 1. Fig. 4 is a transverse section of a modified constructionof the invention.

Similar characters of reference indicate corresponding parts throughout the several views.

1 indicates the action wind chest of tie instrument which may be of any suitable construction; 2 the usual exhausters or feed ers, each having a return spring 3 and l the pedals for operating them through appropriate connections 5, 6. Associated with each exhauster is an equalizer 0r bellows 7 having the usual function of maintaining a substantially uniform tension in the wind chest 1. The exhausters' are supported on the rear side of the customary stationary board or frame 8 arranged transversely in the lower portion of the piano case, while the equalizers are mounted on the front side of said board. As the exhausters, equalizers and accent devices are duplicated, a description of one set will apply toboth.

Each equalizer has a suitable or well known resistance spring 9 and communicates with the corresponding exhauster 2 by a port 10 formed in the board 8 and the fixed rear board 11 of the equalizer and controlled by the usual check valve 12 arranged within the exhauster. In the movable board Specification of Letters Patent.

'Patented Feb. 1, 1921.

Serial No. 195,667.

of the latter is the customary air port 13 to the outer end of which the check valve 14 is applied. The parts thus far described are of ordinary construction. Preferably located upon the board 8 is a transverse wind board or chamber 15 which connects with the a tion chest by a trunk or pipe 16 and with the equalizer 7 by a passage 17 formed in the upper portion of the board 8, the equalizer being in constant communication with the action chest.

Coiiperating with each equalizer is a valved air chamber 18. In its preferred form, this chamber is applied to the face of the movable board 19 of the equalizer and the outer wall 18 of said chamber is fixed and connected with the fixed board 11 of the equalizer by ties or braces 20. The top and side walls of said chamber are flexibly connected with the movable board of the equalby ordinary bellows folds like those of the equalizer, producing practically a double pneumatic or bellows having the intermediaate movable board 19 common to both.

The air chamber 18 communicates with the outer atmosphere by a port 21 controlled by a suitable valve 22 preferably applied to the outer side of the chamber. This valve preferably consists of pallet hinged at its upper end and acted on by a spring 23 which is adapted to hold it open under ordinary or normal pumping of the exhausters 2, but allows it to close wholly or nearly so, under a sudden thrust or abnormal impulse of the corresponding pedal. The spring shown in the drawings consists of a resilient strip fastenedto the back of the valve and projecting above its hinge its upper end, engaging under a hook 24 secured to the wall 18. This spring also extends below the valve and is arranged to engage an adjustable stop or button 25also carried by said wall, whereby the extent of the closing movement of the valve may be regulated, as desired.

Exccpting the port 21 the chamber 18 is closed onall sides. To produce the most satisfactory results, the movable boards of this chamber and the equalizer should be of substantially the same area.

In the use of the apparatus, when the pedals are operated in the ordinary manner to produce a normal air tension in the action chest 1, the pumping bellows 2 exhaust the air from it through the trunk 16, Wind board 15, passage 17, equalizer 7 and port 10. The air is at the same time exhausted from the equalizer whose complete collapse by atmospheric pressure is resisted by its spring 9 in the usual manner. Under these normal pumping conditions, the automatic or check valve 22 of the air chamber 18 remains open, as shown in Fig. 2, its spring 23 having the requisite stiffness for this purpose. The atmosphere is therefore allowed to enter the chamber 18 freely and act upon the outer side of the equalizer which thus performs the usual function without restraint. If. however, the performer gives either of the pedals a sudden, abnormal thrust, the air is exhausted from the corresponding chamber 18 by the quick closing movement of the movable board 19 of the equalizer and the atmospheric pressure thereupon overcomes the resistance of the spring 23 and completely or nearly closes the valve 22, according to the adjustment of the stop 25. The result is that the atmos pheric pressure is momentarily shut off from the chamber 18, preventing such pressure from acting on the equalizer. The exhauster therefore produces-the maximum, unreduced air tension in the action chest, causing the usual striker-pneumatics of the instrument to act with increased -torce and accenting the corresponding note or notes. If desired, several of such abnormal thrusts may be exerted upon the pedals in rapid succession to accentuate a series of notes, as in bringing out a solo part. The moment the performer resumes normal pedaling, the valve 22 opens under the action of its spring, again bringing the equalizers into action and producing normal, reduced tension in the action chest.

This accenting effect is obtained solely by the abnormal impulses received by the pedals, dispensing with separate manually operated-devices for this purpose.

It will be noted that both in accenting and in playing normally, the air is exhausted through the equalizers which have no internal or other valves.

The valves 22 of the chambers 18, being applied to their outer sides, are readily accessible for adjusting or repairing them. If desired, these valves may be allowed to close fully in accenting, but it is preferable to prevent their complete closure by the use of the adjustable stops 25, in order to produce a more resilient and agreeable pumpmg action.

The air chamber 18 is not necessarily in the form of a bellows, as shown in Figs. 1, 2 and 3. If desired, it may be in the form of a rigid casing, as shown at 18*, Fig. 4. As in the construction first described, this casing or chamber has an air inlet port 21 controlled by a valve 22.

Instead of arranging the air chamber on the outer side of the equalizer, the chamber and the equalizer may be located on opposite sides of the fixed board 8, as shown in Fig. 5. In this case, the air chamber 18* which is shown in the form of a bellows, is provided with an air inlet port 21 controlled by a valve 22 18 of this chamber is connected by one or more links 26 with the movable board 19 of the equalizer 7, so that when the equalizer is collapsed more or less by a sudden pressure upon the pedals, the movable board of the air chamber is moved outward, momentarily exhausting the air from the chamber, closing the valve 22 and rendering the equalizer ineflective, as in the first described construction.

I claim as my invention:

1. In an autopneumatic musical instrument, the combination of a wind-chest, an exhauster therefor, an equalizer having a movable Wall and connected with said windchest and the exhauster, and an air chamber, said equalizer having its movable wall exposed to the air in said air chamber, said air chamber having an inlet and a normallyopen valve controlling said inlet and moved toward its closed position by the excess pressure on the outside of said air chamber over that on the inside thereof, under an abnormal action of the exhauster.

2. In an autopneumatic musical instru ment, the combination of a wind-chest, an exhauster therefor, an equalizer having a movable wall and connected with said windchest and the exhauster, and an air chamber having an inlet, said equalizer being located between the exhauster and said air chamber and a normally-open valve controlling said inlet and moved toward its closed position by the excess pressure on the outside of said air chamber over that on the inside thereof, under an abnormal action of the exhauster.

3. In an autopneumatic musical instrument, the combination of a wind chest, an

- exhauster therefor, an equalizer in communication with the wind chest and the ex hauster, an air chamber to the air in which the movable board of the equalizer is exposed, said air chamber having an inlet, an automatic valve applied to said inlet, a spring tending to hold said valve open under the normal action of the exhauster, said spring being attached to the valve and projecting beyond its free end, and an adjustable stop arranged to be engaged by the projecting end of said spring.

CHARLES V. JAMESON.

The movable board 

